If patients with renal diseases had to undergo surgical intervention, they should be prepared in such a way to be in a stable phase of the underlying surgical disease, without any infection, euvolemic, with satisfactory blood pressure and corrected electrolyte balance. These patients need to be hydrated well before intervention, the fall of blood pressure during intervention should be avoided and adequate hydration after the intervention must be continued (taking into account the condition of the kidneys, heart and age of patient). It is assumed that nephrotoxic drugs are to be evaded in renal patients or, if they were necessary, the dosage and dosing interval should be adjusted and prolonged, respectively. The use of radiographic contrast is not advisable, but if required, plentiful hydration will be needed, the least workable contrast dose and, if possible, with lower ionic charge and lower osmolarity will be administered. If surgical intervention was urgent and if there was not enough time for conservative therapy, i.e. correction of electrolytes, volemia, blood pressure and higher values of nitrate substances, a renal patient would be temporarily dialyzed in the immediate preoperative and postoperative course. Any surgical intervention in these patients may aggravate the renal function and bring the patient closer to dialysis treatment. Nevertheless, sometimes the benefit of surgical treatment for the acute surgical disease is higher (especially if it was life-threatening) than the risk of renal function exacerbation and coming closer to dialysis.